Improvement in bung-borers



A. M. NORTON.

BUNG-BORER.' 170,177,742. A Patented May 23,1876,

N.PIEHS. FHOTO-UTHDGRAPHER. WASHINGTON, D, C,

UNITED STATES PATENT OFFICE.

AURELIUS M. NORTON, OF HIGGANUM, ASSIGNOR TO ATWATER E. BROCKETT, OFBRANFORD, CONNECTICUT.

IMPROVEMENT IN BUNG-ABQRERS.

Specification forming part of Letters Patent No. 177,742, dated May 23,1876; application led f March 16, 1876.

To all whom it may concern Be it known that I, AURELIUs M. NORTON, ofHigganuin, in the county of Middlesex and State of Connecticut, haveinvented a new Improvement in Bung-Borers; and l do hereby declare thefollowing, when taken in connection with the accompanying drawings andthe letters .of reference marked thereon, to be a full, clear, and exactdescription of the saine, and which said drawings constitute part ofthis specification, and represent a perspective view.

This invention relates tov an improvement in the article known tothe-trade as bungborersthat is to say, a tapering borer or reamer.

This article is usually made of conical cylindrical form, dividedaxially, and. with a screw-thread at the point, one edge of the bodymade sharp for cutting. A

In the use of this instrument, so soon as the thread at the point haspassed through the head of the barrel or thing being bored, thescrew-thread ceases to draw, and the borer must then be forced by theperson lusing it. i The result is that, as this force must unavoid ablybe irregular, it is very difficult to bore a round hole. p The object ofthis invention is to avoid this difficulty and it consists inconstructing the borer with the screw-thread continued on its rear orexternal surface, as more fully herein` after described. 4

The borer .is ofthe usual conical form, With the-cutting-edge a, andwith a socket, B, for the handle. The tip or point b is alsothreaded inthe usual manner. This thread is continued up throughout the back of theborer, from the edge opposite the cutter, preferably about half-Wayaround to the cutting-edge, as shown in the drawing. This thread followsthe thread of the point, and continues to draw or feed the cut so longas the borer is turned.

The herein-described bung-borer, having a screwthread upon its convexsurface, substan tially as specified.

AURELIUS M. NORTON.

Witnesses:

OORNELIUs BRAINARD, EDWARD D. GILBERT.

